10 Best Outdoor Tankless Water Heaters 2026 in the United States
#1
Winner
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
The Rinnai RXP199iN is a highly efficient tankless water heater that can operate on either propane or natural gas, making it versatile in terms of energy source. With a flow rate of up to 11.1 gallons per minute (GPM), it can supply hot water for multiple fixtures simultaneously, which is great for larger households or outdoor uses where instant hot water is a necessity. Its BTU rating of 199,000 indicates strong heating performance.
Rating
10.0
Chosen by1,211
Energy Efficiency
Installation and Venting
Most important from
119 reviews
#2
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
The Rinnai RX199iN Condensing Smart Sense Tankless Water Heater is a solid choice for those seeking an efficient and high-capacity hot water solution for their home. With a flow rate of up to 11.1 gallons per minute (GPM), this heater can handle multiple fixtures simultaneously, making it ideal for larger households or homes with high hot water demand. Its 199,000 BTU rating ensures that it heats water quickly, maintaining a steady supply.
Rating
9.4
Flow Rate (GPM)
Energy Efficiency
Temperature Rise
Most important from
140 reviews
#3
NEW Rinnai RX180iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 10 GPM, 180,000 BTU
The Rinnai RX180iN is a versatile tankless water heater that operates both indoors and outdoors, powered by natural gas or propane. It delivers a strong flow rate of up to 10 gallons per minute, sufficient to supply hot water to around six fixtures simultaneously, making it suitable for medium to larger households. Its energy efficiency is excellent, with a UEF rating of 0.98, meaning it uses fuel very effectively and helps save on energy costs.
Rating
9.1
Durability and Weather Resistance
Energy Efficiency
Most important from
47 reviews
Top 10 Best Outdoor Tankless Water Heaters 2026 in the United States
#1
Winner
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
NEW Rinnai RXP199iN Smart Sense Condensing Tankless Water Heater, 199,000 BTU, Up to 11.1 GPM, Natural Gas or Propane, Indoor/Outdoor Installation, Built-In Recirculation Pump
Flow Rate (GPM): 11.1
Energy Efficiency: UEF .98
BTU Rating: 199000
Installation and Venting: Professional, outdoor with proper venting
Durability and Weather Resistance: Durable, suitable for various environments
Chosen by 1211 this week
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
NEW Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 11.1 GPM, 199,000 BTU
Flow Rate (GPM): 11.1
Energy Efficiency: .98 UEF
BTU Rating: 199000
Installation and Venting: Versa Vent, professional install
Warranty and Support: robust warranty and support
NEW Rinnai RX180iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 10 GPM, 180,000 BTU
NEW Rinnai RX180iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 10 GPM, 180,000 BTU
Flow Rate (GPM): 10 gallons per minute
Energy Efficiency: 0.98 UEF
BTU Rating: 180000 British Thermal Units
Installation and Venting: Versa Vent system; RX-OVC vent cap
Durability and Weather Resistance: Copper, stainless steel; outdoor resistant
Warranty and Support: 15 years heat exchanger; 5 years parts
NEW Rinnai RX160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU
NEW Rinnai RX160iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 9 GPM, 160,000 BTU
Flow Rate (GPM): 9 Gallons Per Minute
Energy Efficiency: 0.97
BTU Rating: 160,000
Installation and Venting: Indoor/outdoor; pro install; Versa Vent
Durability and Weather Resistance: Outdoor weather resistant if installed properly
Warranty and Support: Reliable warranty and support from Rinnai
NEW Rinnai RX130iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 7.1 GPM, 130,000 BTU
NEW Rinnai RX130iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater, Indoor or Outdoor Water Heater, Up to 7.1 GPM, 130,000 BTU
Flow Rate (GPM): 7.1 gallons per minute
Energy Efficiency: UEF of 0.97
BTU Rating: 130,000 BTU
Temperature Rise: Max temperature 140°F
Installation and Venting: Versa Vent indoor/outdoor install
Durability and Weather Resistance: Outdoor use; extra protection needed
Warranty and Support: Warranty, online resources, installer network
Related Products
Up to 20% off
Rinnai RE199eP Non-Condensing Propane Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Rinnai RE199eP Non-Condensing Propane Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Flow Rate (GPM): 9.8 Gallons Per Minute
Energy Efficiency: Non-condensing; meets SCAQMD 14 ng/J
BTU Rating: 199000 British Thermal Units
Installation and Venting: Outdoor model; professional installation required
Durability and Weather Resistance: Built for outdoor use; weather resistant
Warranty and Support: 15 years heat exchanger; parts and labor
Rinnai RE199eN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Rinnai RE199eN Non-Condensing Natural Gas Tankless Water Heater, Up to 9.8 GPM, Outdoor Installation, 199,000 BTU
Flow Rate (GPM): 7.6
Energy Efficiency: heats water only when necessary
BTU Rating: 199,000
Temperature Rise: significant rise
Installation and Venting: outdoor, professional installation recommended
Durability and Weather Resistance: withstand outdoor conditions
Warranty and Support: heat exchanger 15 years, labor 5 years
FOGATTI InstaShower 8 Plus RV Tankless Water Heater, 3 Door Size Options (15"x15"/15"x18"/18"x18") for Easy Retrofit, 12V DC, Remote Controller, Propane, Ideal for RV Families & Campers, Gen 3
FOGATTI InstaShower 8 Plus RV Tankless Water Heater, 3 Door Size Options (15"x15"/15"x18"/18"x18") for Easy Retrofit, 12V DC, Remote Controller, Propane, Ideal for RV Families & Campers, Gen 3
Flow Rate (GPM): 2.9 Gallons Per Minute
Energy Efficiency: 84%
BTU Rating: 55000 British Thermal Units
Installation and Venting: Three door sizes, pressure valve, remote
Durability and Weather Resistance: Anti-freeze, dry combustion, overheat, overpressure
Rinnai RE180eP Non-Condensing Propane Tankless Water Heater, Up to 8.5 GPM, Outdoor Installation, 180,000 BTU
Rinnai RE180eP Non-Condensing Propane Tankless Water Heater, Up to 8.5 GPM, Outdoor Installation, 180,000 BTU
Flow Rate (GPM): 8.5 gallons per minute
Energy Efficiency: High
BTU Rating: 180,000 BTU
Temperature Rise: Good temperature rise
Installation and Venting: Professional install; outdoor venting needed
Durability and Weather Resistance: Non-condensing; stainless steel; weather resistant
Warranty and Support: 1yr labor, 15yr heat exchanger, 5yr parts
#10
FOGATTI InstaShower 9 Pro RV Tankless Water Heater, 66,000 BTU (Highest Output), Built-in Mixing Tank, 15x15 Inches Black Door, Remote Controller, Ideal for RVers' Everyday Use, Gen 3
FOGATTI InstaShower 9 Pro RV Tankless Water Heater, 66,000 BTU (Highest Output), Built-in Mixing Tank, 15x15 Inches Black Door, Remote Controller, Ideal for RVers' Everyday Use, Gen 3
Flow Rate (GPM): 3.6 gallons per minute
BTU Rating: 66000 British Thermal Units
Installation and Venting: Compact size, fits RV openings, exhaust fan
Durability and Weather Resistance: Alloy steel, anti-freeze, exhaust fan
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Buying Guide for the Best Outdoor Tankless Water Heaters
Choosing the right outdoor tankless water heater can significantly enhance your comfort and convenience, especially if you live in an area where hot water is essential. Tankless water heaters provide hot water on demand, which means you don't have to wait for a tank to fill up and heat. This can save energy and reduce your utility bills. When selecting an outdoor tankless water heater, it's important to consider several key specifications to ensure you get the best fit for your needs.Flow Rate (GPM)Flow rate, measured in gallons per minute (GPM), indicates how much hot water the heater can produce at a given time. This is crucial because it determines whether the heater can meet your household's hot water demands. For example, a flow rate of 3-4 GPM is suitable for small households or single applications like a shower, while 7-10 GPM is better for larger households with multiple simultaneous hot water needs. Assess your household's hot water usage to choose the right flow rate.
Energy EfficiencyEnergy efficiency is measured by the unit's Energy Factor (EF) or Uniform Energy Factor (UEF). This spec indicates how efficiently the heater converts energy into hot water. Higher EF or UEF values mean better efficiency and lower operating costs. Look for models with high efficiency ratings if you want to save on energy bills and reduce your environmental footprint. Consider your usage patterns and prioritize efficiency if you use hot water frequently.
BTU RatingBTU (British Thermal Unit) rating measures the heater's heating capacity. Higher BTU ratings mean the heater can produce more hot water quickly. For larger households or colder climates, a higher BTU rating (e.g., 150,000-200,000 BTUs) is recommended to ensure a steady supply of hot water. For smaller households or warmer climates, a lower BTU rating (e.g., 100,000-150,000 BTUs) may be sufficient. Match the BTU rating to your hot water needs and climate conditions.
Temperature RiseTemperature rise refers to the increase in water temperature that the heater can achieve. This is important because it affects how hot the water will be when it reaches your tap. If you live in a colder area where the incoming water temperature is low, you'll need a heater with a higher temperature rise capability. Typically, a temperature rise of 50-70 degrees Fahrenheit is adequate for most households. Consider your local water temperature and desired hot water temperature to choose the right model.
Installation and VentingOutdoor tankless water heaters require proper installation and venting to ensure safe and efficient operation. Some models are easier to install and come with venting kits, while others may require professional installation. Consider the complexity of installation and whether you are comfortable doing it yourself or if you need professional help. Proper venting is crucial to prevent carbon monoxide buildup and ensure the heater operates efficiently. Check the installation requirements and choose a model that fits your installation capabilities.
Durability and Weather ResistanceSince outdoor tankless water heaters are exposed to the elements, durability and weather resistance are important factors. Look for models with robust construction, corrosion-resistant materials, and weatherproof features to ensure longevity. Some heaters come with protective enclosures or are designed to withstand extreme temperatures. If you live in an area with harsh weather conditions, prioritize models with high durability and weather resistance to ensure reliable performance.
Warranty and SupportA good warranty and reliable customer support can provide peace of mind and protect your investment. Warranties typically cover parts and labor for a certain period, and longer warranties indicate confidence in the product's quality. Check the warranty terms and the availability of customer support services. Choose a model with a comprehensive warranty and good support to ensure you can get help if any issues arise.